A long term evolution (LTE) network supports six types of standard bandwidth: 1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz, and 20 MHz. A global system for mobile communications (GSM)/universal mobile telecommunications system (UMTS)/code division multiple access (CDMA) network cannot satisfy requirements of intelligent terminals on massive voice and data services. Therefore, the intelligent terminals rapidly migrate towards an LTE network, and consequently, load of the GSM/UMTS/CDMA network is gradually reduced and load of the LTE network is gradually increased. To properly configure resources, operators try to release spectrums originally used for the GSM/UMTS/CDMA network, so that the spectrums are used for the LTE network, to improve spectral efficiency and a data throughput. Bandwidth of GSM/UMTS/CDMA is not standard bandwidth of the LTE network. Therefore, use of non-standard bandwidth becomes an important application scenario of LTE.
In some application scenarios of non-standard bandwidth, in the LTE network, the foregoing standard bandwidth needs to be compressed into non-standard bandwidth to use. Consequently, some resource blocks (RB) in the standard bandwidth are lost due to compression. As shown in FIG. 1, standard bandwidth before compression includes an RB 1, an RB 2, an RB 3, . . . , an RB (n−1), and an RB n, and the standard bandwidth after compression includes the RB 2, the RB 3, . . . , the RB (n−1), and the RB n. A structure of an RB is shown in FIG. 2, there is one CRS at an interval of every six subcarriers in a frequency domain, and there is one CRS at an interval of every three symbols in a time domain. If some RBs are lost due to compression, CRSs in the RBs are damaged. A channel estimation mechanism in the prior art is: A base station schedules an RB for a terminal. The terminal selects another RB from standard bandwidth to which the scheduled RB (an RB currently scheduled to the terminal) belongs, and then performs channel estimation by using a CRS in the scheduled RB and a CRS in the another RB.
A disadvantage in the prior art is that if a base station schedules, to a terminal, an RB (also referred to as a “compressed RB”) in non-standard bandwidth obtained through compression on standard bandwidth, the terminal may determine a range that is of the standard bandwidth and within which the compressed RB falls, then select another RB from the standard bandwidth, and perform channel estimation based on a CRS in the compressed RB and a CRS in the another RB. If the another RB selected from the standard bandwidth is an RB lost due to compression, a channel estimation result of the terminal is inaccurate, and consequently, a demodulation result of a data demodulation service performed based on the channel estimation result has a relatively large error.